[gtk+/icon-shadow: 3/9] themingengine: add gtk_theming_engine_render_icon()

[Cosimo Cecchi <cosimoc src gnome org>]

commit 5735f6e7c6e38516e16104b1675a9bb913542f64
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Fri May 20 23:50:47 2011 -0400

    themingengine: add gtk_theming_engine_render_icon()

 gtk/gtkthemingengine.c |  130 ++++++++++++++++++++++++++++++------------------
 gtk/gtkthemingengine.h |    9 +++-
 2 files changed, 90 insertions(+), 49 deletions(-)
---
diff --git a/gtk/gtkthemingengine.c b/gtk/gtkthemingengine.c
index 47833a3..ea09693 100644
--- a/gtk/gtkthemingengine.c
+++ b/gtk/gtkthemingengine.c
@@ -176,6 +176,13 @@ static void gtk_theming_engine_render_activity  (GtkThemingEngine *engine,
 static GdkPixbuf * gtk_theming_engine_render_icon_pixbuf (GtkThemingEngine    *engine,
                                                           const GtkIconSource *source,
                                                           GtkIconSize          size);
+static void gtk_theming_engine_render_icon (GtkThemingEngine *engine,
+                                            cairo_t *cr,
+                                            gdouble x,
+                                            gdouble y,
+                                            gdouble width,
+                                            gdouble height,
+					    GdkPixbuf *pixbuf);
 
 G_DEFINE_TYPE (GtkThemingEngine, gtk_theming_engine, G_TYPE_OBJECT)
 
@@ -214,6 +221,7 @@ gtk_theming_engine_class_init (GtkThemingEngineClass *klass)
   object_class->set_property = gtk_theming_engine_impl_set_property;
   object_class->get_property = gtk_theming_engine_impl_get_property;
 
+  klass->render_icon = gtk_theming_engine_render_icon;
   klass->render_check = gtk_theming_engine_render_check;
   klass->render_option = gtk_theming_engine_render_option;
   klass->render_arrow = gtk_theming_engine_render_arrow;
@@ -3069,53 +3077,24 @@ lookup_icon_size (GtkThemingEngine *engine,
   return gtk_icon_size_lookup_for_settings (settings, size, width, height);
 }
 
-/* Kudos to the gnome-panel guys. */
 static void
-colorshift_pixbuf (GdkPixbuf *src,
-                   GdkPixbuf *dest,
-                   gint       shift)
-{
-  gint i, j;
-  gint width, height, has_alpha, src_rowstride, dest_rowstride;
-  guchar *target_pixels;
-  guchar *original_pixels;
-  guchar *pix_src;
-  guchar *pix_dest;
-  int val;
-  guchar r, g, b;
-
-  has_alpha       = gdk_pixbuf_get_has_alpha (src);
-  width           = gdk_pixbuf_get_width (src);
-  height          = gdk_pixbuf_get_height (src);
-  src_rowstride   = gdk_pixbuf_get_rowstride (src);
-  dest_rowstride  = gdk_pixbuf_get_rowstride (dest);
-  original_pixels = gdk_pixbuf_get_pixels (src);
-  target_pixels   = gdk_pixbuf_get_pixels (dest);
-
-  for (i = 0; i < height; i++)
-    {
-      pix_dest = target_pixels   + i * dest_rowstride;
-      pix_src  = original_pixels + i * src_rowstride;
+colorshift_source (cairo_t *cr,
+		   gdouble shift)
+{
+  cairo_pattern_t *source;
 
-      for (j = 0; j < width; j++)
-        {
-          r = *(pix_src++);
-          g = *(pix_src++);
-          b = *(pix_src++);
+  cairo_save (cr);
+  cairo_paint (cr);
 
-          val = r + shift;
-          *(pix_dest++) = CLAMP (val, 0, 255);
+  source = cairo_pattern_reference (cairo_get_source (cr));
 
-          val = g + shift;
-          *(pix_dest++) = CLAMP (val, 0, 255);
+  cairo_set_source_rgb (cr, shift, shift, shift);
+  cairo_set_operator (cr, CAIRO_OPERATOR_COLOR_DODGE);
 
-          val = b + shift;
-          *(pix_dest++) = CLAMP (val, 0, 255);
+  cairo_mask (cr, source);
 
-          if (has_alpha)
-            *(pix_dest++) = *(pix_src++);
-        }
-    }
+  cairo_pattern_destroy (source);
+  cairo_restore (cr);
 }
 
 static GdkPixbuf *
@@ -3129,6 +3108,8 @@ gtk_theming_engine_render_icon_pixbuf (GtkThemingEngine    *engine,
   GtkStateFlags state;
   gint width = 1;
   gint height = 1;
+  cairo_t *cr;
+  cairo_surface_t *surface;
 
   base_pixbuf = gtk_icon_source_get_pixbuf (source);
   state = gtk_theming_engine_get_state (engine);
@@ -3156,16 +3137,36 @@ gtk_theming_engine_render_icon_pixbuf (GtkThemingEngine    *engine,
     {
       if (state & GTK_STATE_FLAG_INSENSITIVE)
         {
-          stated = gdk_pixbuf_copy (scaled);
-          gdk_pixbuf_saturate_and_pixelate (scaled, stated,
-                                            0.8, TRUE);
-          g_object_unref (scaled);
+	  surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+						gdk_pixbuf_get_width (scaled),
+						gdk_pixbuf_get_height (scaled));
+	  cr = cairo_create (surface);
+	  gdk_cairo_set_source_pixbuf (cr, scaled, 0, 0);
+	  cairo_paint_with_alpha (cr, 0.5);
+
+	  cairo_destroy (cr);
+
+	  g_object_unref (scaled);
+	  stated = gdk_pixbuf_get_from_surface (surface, 0, 0,
+						cairo_image_surface_get_width (surface),
+						cairo_image_surface_get_height (surface));
         }
       else if (state & GTK_STATE_FLAG_PRELIGHT)
         {
-          stated = gdk_pixbuf_copy (scaled);
-          colorshift_pixbuf (scaled, stated, 30);
-          g_object_unref (scaled);
+	  surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+						gdk_pixbuf_get_width (scaled),
+						gdk_pixbuf_get_height (scaled));
+
+	  cr = cairo_create (surface);
+	  gdk_cairo_set_source_pixbuf (cr, scaled, 0, 0);
+	  colorshift_source (cr, 0.10);
+
+	  cairo_destroy (cr);
+
+	  g_object_unref (scaled);
+	  stated = gdk_pixbuf_get_from_surface (surface, 0, 0,
+						cairo_image_surface_get_width (surface),
+						cairo_image_surface_get_height (surface));
         }
       else
         stated = scaled;
@@ -3175,3 +3176,36 @@ gtk_theming_engine_render_icon_pixbuf (GtkThemingEngine    *engine,
 
   return stated;
 }
+
+static void
+gtk_theming_engine_render_icon (GtkThemingEngine *engine,
+                                cairo_t *cr,
+                                gdouble x,
+                                gdouble y,
+                                gdouble width,
+                                gdouble height,
+				GdkPixbuf *pixbuf)
+{
+  GtkStateFlags state;
+  GtkShadow *icon_shadow;
+
+  state = gtk_theming_engine_get_state (engine);
+
+  cairo_save (cr);
+  gdk_cairo_set_source_pixbuf (cr, pixbuf, x, y);
+
+  gtk_theming_engine_get (engine, state,
+                          "icon-shadow", &icon_shadow,
+                          NULL);
+
+  if (icon_shadow != NULL)
+    {
+      _gtk_icon_shadow_paint (icon_shadow, cr);
+      _gtk_shadow_unref (icon_shadow);
+    }
+
+  cairo_paint (cr);
+
+  cairo_restore (cr);
+}
+
diff --git a/gtk/gtkthemingengine.h b/gtk/gtkthemingengine.h
index b1d4b95..5f60e9e 100644
--- a/gtk/gtkthemingengine.h
+++ b/gtk/gtkthemingengine.h
@@ -168,9 +168,16 @@ struct _GtkThemingEngineClass
   GdkPixbuf * (* render_icon_pixbuf) (GtkThemingEngine    *engine,
                                       const GtkIconSource *source,
                                       GtkIconSize          size);
+  void (* render_icon) (GtkThemingEngine *engine,
+                        cairo_t          *cr,
+                        gdouble           x,
+                        gdouble           y,
+                        gdouble           width,
+                        gdouble           height,
+			GdkPixbuf        *pixbuf);
 
   /*< private >*/
-  gpointer padding[16];
+  gpointer padding[15];
 };
 
 GType gtk_theming_engine_get_type (void) G_GNUC_CONST;